STEALTHMARK · HEAD TO HEAD

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Claude Fable 5.1 vs Union Alpha

Claude Fable 5.1 scores 2.1 points higher overall (62.1 vs 60.0). Claude Fable 5.1 leads General Intelligence; Union Alpha leads Visual Intelligence. Claude Fable 5.1 scores higher on Newton's Mirror, with its largest category advantage in reflections. Union Alpha’s overall score includes one estimated scene.

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Overall StealthMark

62.1/100
60.0/100Estimated · 1 missing scene

General Intelligence

54.3/100
40.9/100Partial coverage

Visual Intelligence

67.7/100
73.2/100Partial coverage

Newton's Mirror

Same prompt

Physics, perspective and recursive reflections, tested together. Explore the test ↗

Claude Fable 5.151.7/100

Claude Fable 5.1: Newton's Mirror SVG benchmark
Researcher observations

The broad paint sequence, bilateral near-field sphere arrangement, overlaps and diminishing panel repetitions are recognizable; crimson is slightly too low. Small paint scale and basic shading provide material cues, although the steel response remains soft. Inaccurate light projections, missing outer chains and incomplete nested room imagery remain the principal limitations.

Prompt withheld

This prompt is held back to prevent benchmaxxing.

Union Alpha38.3/100

Union Alpha: Newton's Mirror SVG benchmark
Researcher observations

Recognizable near-field sphere placement and bilateral convergence provide limited optical structure. Broad gray regions interrupt lateral sightlines and truncate side-floor images. Missing outer chains, absent nested sphere imagery and incomplete planar and curved emitter mappings dominate the reflection system.

Prompt withheld

This prompt is held back to prevent benchmaxxing.

Compare category scores
CategoryClaude Fable 5.1Union Alpha
State at 600 ms24.0/2525.0/25
Camera and placement14.0/1515.0/15
Reflections48.0/12019.0/120
Materials and scale7.0/1010.0/10
Floor-damage reward0.0/100.0/10

Selfie

Claude Fable 5.169.0/100

Claude Fable 5.1: Selfie SVG benchmark
Researcher observations

The coral palette, friendly face, matte shading and cream arch create a coherent emblem. However, the mantle is elongated rather than compact, and the appendages spread mostly sideways and downward instead of forming an evenly spaced, flower-like starburst. Two thin hanging appendages weaken the thick-arm motif. Clean contours and balanced framing support the simple design.

Prompt withheld

This prompt is held back to prevent benchmaxxing.

Compare category scores
CategoryClaude Fable 5.1Union Alpha
Prompt & likeness6.5/10—
Anatomy & construction6.5/10—
Space & placement7.5/10—
Light & reflections6.5/10—
Purposeful detail6.0/10—
Artistry & character7.5/10—
Materials & effects6.5/10—
Visual integrity8.0/10—

Beach

Different prompts

Claude Fable 5.175.0/100

Claude Fable 5.1: Beach SVG benchmark
Researcher observations

The colorful sunset, layered shoreline, animals, kite and beach toys fulfill the lively beach brief. Clean silhouettes and a balanced composition give the illustration character. Construction is simplified: the umbrella resembles a segmented fan, dolphins have weak water interaction, and the sun’s reflection forms a rigid widening wedge. Flat surfaces and sparse contact shadows limit depth.

Exact prompt

Create an SVG of a amazing beach scene. Sunset, animals, fun, birds, reflections Make it a masterpiece, no tools allowed

Union Alpha80.0/100

A beach at sunset with a palm tree, turtle, crab, birds, and a leaping dolphin.
Researcher observations

A cohesive sunset palette, sweeping shoreline and playful animals make an appealing beach illustration. The sun’s reflection establishes a clear focal axis, balanced by the palm and umbrella. Clean silhouettes and small decorative features reward inspection, though simplified anatomy, repetitive reflection bars and generic oval shadows limit volume and naturalism.

Exact prompt

Create an SVG of a amazing beach scene. Sunset, animals, fun, birds, reflections

Compare category scores
CategoryClaude Fable 5.1Union Alpha
Prompt & likeness8.5/109.0/10
Anatomy & construction7.0/107.5/10
Space & placement7.0/108.0/10
Light & reflections7.0/107.5/10
Purposeful detail7.5/108.0/10
Artistry & character8.0/108.0/10
Materials & effects6.5/107.0/10
Visual integrity8.0/108.5/10

Mona Lisa

Different prompts

Claude Fable 5.156.5/100

Claude Fable 5.1: Mona Lisa SVG benchmark
Researcher observations

The dark clothing, crossed hands and hazy landscape establish the Mona Lisa composition. Replication is limited by the frontal, elongated face, wide eyes and simplified smile. Rounded, parallel fingers and unclear wrist transitions weaken the hands. Warm facial shading gives some volume, but broad garment shapes and scattered crack marks substitute for convincing folds and painterly detail.

Exact prompt

Replicate mona-lisa as SVG Make it a masterpiece, no tools allowed

Union Alpha64.0/100

An SVG interpretation of the Mona Lisa, with folded hands and a landscape background.
Researcher observations

The centered portrait, folded hands, dark clothing and hazy landscape clearly evoke the Mona Lisa. Muted colors and soft facial shading create a coherent illustration, but replication remains schematic: the face is broad, eyes outlined, smile simplified and overlapping fingers poorly resolved. Angular landscape shapes and flat fabric limit depth and painterly richness.

Exact prompt

Replicate mona-lisa as SVG

Compare category scores
CategoryClaude Fable 5.1Union Alpha
Prompt & likeness6.0/107.0/10
Anatomy & construction5.0/106.0/10
Space & placement6.0/106.5/10
Light & reflections6.0/106.5/10
Purposeful detail5.0/105.5/10
Artistry & character5.5/106.5/10
Materials & effects5.5/105.0/10
Visual integrity6.5/107.5/10

Raccoon

Different prompts

Claude Fable 5.170.8/100

Claude Fable 5.1: Raccoon SVG benchmark
Researcher observations

The raccoon rides on the dog's back, and the dog's extended foreleg reaches the jet ski controls. Expressive faces, a clear silhouette and sweeping spray make the action readable. Limb and handlebar overlaps weaken construction; broad shading provides limited volume, and the glowing sun has little corresponding reflection on the water. Clean vector shapes support an appealing but simplified illustration.

Exact prompt

Generate an SVG: A raccoon sits on a dog's back while the dog steers a jet ski Make it a masterpiece, no tools allowed

Union Alpha72.0/100

A raccoon rides on a dog as the dog steers a red jet ski.
Researcher observations

Expressive animals, a readable riding arrangement and sweeping spray create an appealing cartoon. The raccoon sits convincingly on the dog's back, but the dog's paw does not clearly grip the handlebar, whose connection to the hull is unresolved. Flat lighting provides little volume or reflection. A dark rectangular strip interrupts the upper-right background.

Exact prompt

A raccoon sits on a dog's back while the dog steers a jet ski

Compare category scores
CategoryClaude Fable 5.1Union Alpha
Prompt & likeness8.5/108.0/10
Anatomy & construction6.5/106.5/10
Space & placement7.0/107.5/10
Light & reflections5.5/105.5/10
Purposeful detail7.0/107.5/10
Artistry & character7.5/108.0/10
Materials & effects6.5/107.5/10
Visual integrity7.5/107.0/10

Pelican

Benchmax control

Outside General and Visual Intelligence.

Claude Fable 5.172.3/100

Claude Fable 5.1: Pelican SVG benchmark
Researcher observations

The pelican reads clearly, with an expressive face, prominent bill and appealing composition. Both legs connect to the body, but the far foot's pedal contact and the wing's steering grip remain unclear. Wheel alignment and background layers are coherent. Clean contours and feather lines give polish, while schematic machinery, limited surface texture and weak directional lighting constrain the finish.

Exact prompt

Generate an SVG of a pelican riding a bicycle Make it a masterpiece, no tools allowed

Union Alpha73.8/100

A pelican riding a teal bicycle beneath a sunny blue sky.
Researcher observations

The pelican is immediately recognizable, with an expressive face, convincing bill silhouette and appealing pastel composition. Both legs connect to feet, and the wing reaches the handlebar. Bicycle construction is less resolved: the far pedal lacks a clear crank connection and no chain is visible. Clean contours and orderly spokes support the illustration, while flat lighting and simplified surfaces limit depth.

Exact prompt

Generate an SVG of a pelican riding a bicycle

Compare category scores
CategoryClaude Fable 5.1Union Alpha
Prompt & likeness8.5/108.5/10
Anatomy & construction6.5/106.5/10
Space & placement7.5/107.5/10
Light & reflections6.0/106.0/10
Purposeful detail7.0/107.0/10
Artistry & character7.5/108.0/10
Materials & effects6.0/106.5/10
Visual integrity8.0/108.5/10